The United Nations Office on Drugs and Crime released the latest statistics in its 2013 World Drug Report Wednesday during a Commission on Narcotic Drugs event in Vienna, the U.N. News Center reported.
The report found that use of untested psychoactive substances, known by names such as "spice," "plant food," "bath salts" and "meow meow," can be toxic, causing "delirium and violent behavior."
"There is an alarming new drug problem," Office on Drugs and Crime Executive Director Yury Fedotov said.
The report found the number of these substances grew from 166 at the end of 2009 to 251 by mid-2012.
"Given the almost infinite scope to alter the chemical structure of NPS, new formulations are outpacing efforts to impose international control," Fedotov said.
The office has started an early-warning system the United Nations said will allow the global community to monitor their emergence and take appropriate actions.